Genesis 38:3,6,7
And she conceived, and bore a son; and he called his name Er.
Nave's Topical Index—AKJV

Genesis 46:12
And the sons of Judah; Er, and Onan, and Shelah, and Pharez, and Zarah: but Er and Onan died in the land of Canaan. And the sons of Pharez were Hezron and Hamul.
Nave's Topical Index—AKJV

Numbers 26:19
The sons of Judah were Er and Onan: and Er and Onan died in the land of Canaan.
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1 Chronicles 2:3
The sons of Judah; Er, and Onan, and Shelah: which three were born to him of the daughter of Shua the Canaanitess. And Er, the firstborn of Judah, was evil in the sight of the LORD; and he slew him.
Nave's Topical Index—AKJV